Hi, I am currently building a multi-platform app which supports a tiered subscription to additional features for customers which hold a specific amount of tokens in their Ethereum wallet. The core product is free and any additional features are optional. My question would be how to set this up such that it follows App Store purchase guidelines? I see in the dev guidelines (https://developer.apple.com/app-store/review/guidelines/#multiplatform-services) that if we wanted to support any features that are "unlocked", we must also set up a route for in-app purchase with Apple. The subscription tokens are not tied to a specific USD amount, so the total price of each subscription tier is variable. Does anyone have any guidance on if this business model could work? What about setting up an in-app purchase with a price that is tied to a non-USD asset? Thanks in advance!